CVE-2026-74431Network attack vector

Remote thread hang via ignored OOB queue

Published Aug 15, 2026 · Updated Aug 15, 2026

Denial of service in Linux kernel 6.16 RxRPC allows remote attackers to hang a calling thread through a crafted CHALLENGE. rxrpc_recvmsg() checks only recvmsg_q before waiting and ignores queued out-of-band data, repeatedly re-entering its retry path instead of consuming the OOB item. Exploitation requires an established RxRPC client connection to a malicious or compromised AFS/YFS server; the loop can saturate one CPU core.

CVSS severity7.5
High
EPSS probability0.34%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Linux kernel 6.16 RxRPC allows remote attackers to hang a calling thread through a crafted CHALLENGE. rxrpc_recvmsg() checks only recvmsg_q before waiting and ignores queued out-of-band data, repeatedly re-entering its retry path instead of consuming the OOB item. Exploitation requires an established RxRPC client connection to a malicious or compromised AFS/YFS server; the loop can saturate one CPU core.

The record

CVE
CVE-2026-74431
Published
Aug 15, 2026
Updated
Aug 15, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-835, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 15, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5800b1cf3fd8ccab752a101865be1e76dac33142 <0fc5b37faec26241d3cbee732e29ac35ad3184f8
  2. Affected versionversion=5800b1cf3fd8ccab752a101865be1e76dac33142 <67a0332f442ef07713cd2d9c13d59db0f1c23648
  3. Affected versionversion=5800b1cf3fd8ccab752a101865be1e76dac33142 <da371b003a4a44f44741275d5e8dc74181cbb017
  4. Affected versionversion=6.16

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5800b1cf3fd8ccab752a101865be1e76dac33142 <0fc5b37faec26241d3cbee732e29ac35ad3184f8; version=5800b1cf3fd8ccab752a101865be1e76dac33142 <67a0332f442ef07713cd2d9c13d59db0f1c23648; version=5800b1cf3fd8ccab752a101865be1e76dac33142 <da371b003a4a44f44741275d5e8dc74181cbb017; version=6.16

Published CVSS scores

7.5cve.orgCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.5Red HatCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-835Loop with Unreachable Exit Condition ('Infinite Loop')
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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